The water Ambedkar could not drink
As a schoolboy at Satara, B.R. Ambedkar and his siblings were forbidden to touch the common water tap or drinking vessel because they were untouchable; they stayed thirsty unless a caste-Hindu peon chose to pour water from a height into their cupped hands, and on days he was absent they went without. Access to a basic bodily need was made contingent on the goodwill of a person higher in the caste order.